In his book The Master Switch[0], he makes a similar argument, though in the case of this, it was open access and net neutrality, but I think the overall message and patterns around that he talks about, it is very much similar to whats being talk about by Doctorow. The sum of his argument maintains that basically open systems allow for high periods of innovation, experimentation, and ultimately new markets, and eventually, when those open systems start to get dominated by a few players, they tend to close and become entrenched, until they stagnant, and become open again. He also suggests, as part of the conclusion of his book, that if as society it is encouraged, for instance, for base systems to be open, you don't have to sacrifice interim innovation and growth that come with open systems, and therefore encouraging innovation across all affected sectors.
Think about it like this. Large companies were once small, and when they were small, they built their backs on reverse engineering proprietary protocols and using open access systems, in which they were able to innovate in these spaces, while also able to maintain that innovation catalyst by inter-operating with common systems (e.g TCP/IP, HTTP) and reverse engineering proprietary protocols. In the case of Apple, for instance, one of their primary motivations in investing in AppleWorks[1] is that they actively reversed engineered the Microsoft Office formats, which afforded interoperability with PCs. Arguably, without open access systems and the ability to reverse engineer these formats, Apple would not be where it is today. However now, legislation and legal precedent has been set that would be it, at best, dubiously legal, for a competitor to do just that.
[0]: He gave a talk at Stanford based on the ideas of the book, which centered around net neutrality and open protocols, you can see that talk on YouTube: https://www.youtube.com/watch?v=ij76dh_340w